The main objectives of the proposed research are to study the ecology and epidemiology of wildlife rabies. This would include (1) an intensive search for rodent reservoirs of rabies virus and (2) a study of natural resistance, immunity, latency and carrier states for rabies, with a major emphasis on rodents and skunks, but also including racoons, opossums, and other small carnivores in the study. Large numbers of rodents will be live trapped, bled and processed for rabies virus isolation. Serum neutralization tests will be conducted on the sera to determine if rabies antibodies titers are present. Five serial blind passages in mice and tissue culture (BHK 21) will be carried out with brain, salivary glands and brown fat. Smaller numbers of skunk, raccoon and opossum tissues will be processed in a similar manner. If rodent rabies isolates are found in the United States they will be compared serologically and biologically to rodent rabies isolates obtained from European laboratories. A pen study with skunks will be continued. Approximately 80 skunks were captured, descented and held. Periodic serum and cerebral spinal fluid rabies serum neutralization tests are being conducted. The skunks are then being treated with Dexamethasone, as a physiological stress factor, in attempts to exacerbate latent infections in the test animals. Cellular immunity to rabies will be studied in a mouse model system. Limited studies on skunks will be conducted.